The purpose of this project is to explore the great variety and abundance of the marine environment for molecular models of neurobiology. In particular, to investigate species or phenomena which display an amplification or simplification of human physiology or pathology. Typical examples studied in this project are: sea urchin embryos in membranogenesis and development, CNS degeneration in spawning Pacific salmon, and use of the large nerve bundle of the lobster walking leg. We have localized membrane ATPases of sea urchin gametes using covalent probes and plasma membrane preparations. We discovered that DDT and certain other pesticides inhibit divalent cation-stimulated ATPases. Both covalent probes and pesticides prevent cell division of sea urchin embryos.